Disclaimer: I do not own the characters. All rights belong to NBC. Nor do I own the song Butterfly Kisses. All rights belong to Bob Carlisle, Randy Thomas, and Larry Day.

-x-

It's four in the afternoon as Matthew Casey opens the door to his home. He had just finished a construction gig and all he wanted to do was shower and spend the rest of the day lying on the couch with Gabby in his arms. They had gotten married three months ago. As he remembers the day, a smile graces Casey's face .

Chaplain Orlovsky had accepted their request to officiate the ceremony and they were surrounded by all of their family and friends. Even his mother had shown up, much to his surprise. He hadn't seen or heard from her in months, but she quickly embraced Gabby, going on and on about how she couldn't miss this wedding. She was always rooting for he and Gabby. Always hoping the two would get their acts together. He couldn't help but laugh at her antics. She was right, he'd give her that.

Casey is brought out of his memory when he hears movement in the bedroom. "Gabby, I'm home," he calls out as he places his duffel bag on the floor by the door. He then kicks off his shoes and makes his way through their apartment. The silence he is met with is unsettling. "Gabby?" he calls out, his voice laced with concern. He finds her sitting on the edge of the bathtub. He knew she hadn't been feeling well lately. Most mornings began with her head hovered over the toilet bowl, and he silently hoped that he wouldn't have to spend another day holding her hair back while her stomach emptied itself. He was willing to do it, but he hated seeing his girl so sick.

He squats down in front of her so he could meet her big brown eyes with his own. "Baby, what's wrong?" he gently whispers. He has seen that distant look in her eyes before and he braces himself for whatever she is about to tell him. The sound of his voice takes her out of her distant stare as she is met with those beautiful blue eyes that she knew by heart. Those eyes made her weak, though she'd never admit that to him.

She smiles softly at him, careful not to reveal too much emotion, her mind racing with her thoughts.

Is it too soon? Are they ready? What if it's not the right time? What if they can't make it work? They hadn't been trying. It just happened. God, was she ecstatic, but she'd be lying if she said a small part of her wasn't petrified.

She picks herself up from the edge of the tub and begins pacing in their bedroom, Casey looking on dumbfoundedly, temporarily rooted to his spot on the bathroom floor. Seconds later, his worry swelling with every step Gabby takes, he leaves his spot on the floor, walking over to her, placing his strong hands on her shoulders and steadying her movements. She looks up at him and for a second Casey swears he can see fear flash across her features.

"You know whatever it is you can tell me. Right? We will figure it out together," he says with a nonchalant shrug of his shoulders. They'd been through hell together, what was one more bump in the road?

Together. Gabby knows he is right. This is a good thing. A great thing. They'll make it work.

As her eyes look for his once more, she watches as he sends her a small smirk, dimples in tow. Boy, he knew her well. A smirk from him could calm her down in ways she could never quite explain. With that bit of reassurance she takes a deep breath, nervously looking anywhere but at his face, and opens her mouth to speak.

"I'm pregnant," she manages to whisper.

"We're pregnant." This time her voice was stronger. As she felt the familiar hands on her shoulders drop, she quickly looked up to catch Casey's reaction to her news. He was staring straight at her, his facial expression reading more of shock than she had hoped for. Seconds later a smile quickly forms on his face and suddenly he is lifting her up in his arms and twirling her around their bedroom, giggles escaping both of their lips. Only after he sets her back down on the ground does she realize that he has tears in his eyes. He doesn't bother to wipe them away.

"I'm gonna be a dad," he breathes out.

He's not sure he's ever been this happy.

-x-

He's not sure he's ever been this terrified.

One minute he's sleeping and the next minute Gabby is frantically shaking him awake, shouting that her water had broke. His body moves at record speed as he quickly latches on to Gabby, directing her out the door and into his truck. She's breathing and screaming and breathing and screaming and he doesn't mean to have a goofy grin on his face but he just can't help it. His baby girl is coming. He's finally going to meet her. After months of feeling her kick and talking to Gabby's stomach he's finally going to get to hold her.

They're minutes away from the hospital, stuck at a red light, when he turns to catch a glimpse of his wife. Even in labor she was beautiful. He quickly sent up a prayer to whoever was listening that his baby would look just like her. His two perfect girls. Gabby looks over at him in between her deep breaths and smiles. This is it.

Hours later Gabby is tightly clutching his hand and he's not quite sure he'll ever fully regain the feeling back. He's whispering into her ear, telling her that she's doing great, that she's almost there, offering words of encouragement. It all happens so fast. With every push he feels his doubt creeping in closer. What if he's a terrible father, or worse, what if he's like his father? He makes a vow right then and there, in the hospital delivery room, that he will always be there for his daughter. No matter what. He will listen to her when she wants to vent, be a shoulder for her to cry on, and be a constant source of support for her as she molds herself into the woman she wants to be. He will never belittle her ambition. Never make her feel less than perfect. He will make sure that she knows, every single day, just how much she is loved. How much she is adored. How he has waited his entire life for her to come into his world.

She'll know that she'll always be his little girl, no matter how old she gets, and that he will love her until the end of time.

He's busy in his thoughts when he hears it for the first time. The sound of her crying. It's all a blur from that point on as the doctors and nurses congratulate him and Gabby on the birth of their baby girl. Then he's kissing Gabby's sweaty forehead and holding her as if his life depended on it. Both far too eager to meet their little joy.

"You did it, baby. She's here. She's really here. I'm so proud of you," he tells her as he peppers her face with light kisses. Moments later the doctor comes over, baby in hand, and places her down in Gabby's arms.

He's not sure he'll ever stop looking at her. She has his blonde hair and Gabby's big brown eyes. She's perfect and she's theirs.

"We did good," Gabby jokes, the tears streaming down her face.

"We did good," Casey repeats, his own tears falling down his face as he studies his beautiful little girl. He's completely mesmerized. He won't even bother denying it. He knows in this moment that whatever she asks for in her lifetime he will move mountains to give it to her. As he looks over at his two girls he wonders how he got so lucky. He leans into Gabby, placing one more kiss on her forehead, as he then bends down to kiss his little girl. He starts with her tiny hands, placing light kisses on each one, then he moves to her tiny nose, placing a kiss there and finally her forehead.

"Welcome to the world, Leslie Rose."

He takes it back. This moment. This moment is the happiest he has ever been.

-x-

The entire 51 family is waiting back at their house the day they bring Leslie home. They decorated the house for them and all share their excitement about meeting the tiniest, newest member of the family. Casey watches on as Severide holds his baby girl, spending some time with her before he passes her on to Herrmann and Cindy, then to Chief, and before he knows it each member of the firehouse has held her. He steals a glance at Gabby, who is also watching on, and he knows how bittersweet this moment is for her. Shay would have eaten their little girl up. He just knows it, and one day he will make sure that Leslie Rose knows too. He and Gabby both will tell her all about her namesake.

As great as it is to have his extended family in the house, he can't wait until they leave. He just wants some alone time with his new family. He knows he's already in too deep, but he's waited a lifetime for Leslie and he wants to hold her while she's still small enough to be cradled in his arms.

He jumps on the opportunity to feed her while Gabby says goodbye to all of their friends. He carries her into her nursery, flicking on the dim light that he had installed weeks ago, and makes his way over to the rocking chair. He had spent months on this room, making sure that everything was just right. Gabby had teased him about spoiling the baby before she was even born but he didn't mind. Of course he would spoil her. She was his little princess. As he settles in the chair, she begins to stir in his arms. "I know, baby girl," he says soothingly, "here you go." He gives her a bottle, smiling as she begins to drink, her eyes slowly shutting as she drifts off to sleep. He watches as her tiny eyes flutter until they close and he can't help but smile.

He'll never get used to her.

Gabby makes her way towards the nursery about an hour later, having taken the free time to tidy the house and get herself ready for bed. As she slowly opens the door, her heart leaps in her chest at the sight in front of her. There was Casey in the rocking chair. His own eyes were closed and Leslie was snuggled into his chest, her tiny fingers somehow wrapped around Casey's forefinger.

With tears in her eyes Gabby watches on, unwilling to ruin such a perfect moment.

-x-

People always say kids grow up fast, but he never truly understood what it meant until his baby girl wasn't a baby anymore.

He can't believe how quickly it went. It feels like only days ago he was holding her in his arms, singing her to sleep, and now she's off to start her first day as a fifth grade student.

They have a routine. It's been theirs since she started pre-school years ago. On the days when he is not on shift he walks with her to school. He calls it daddy and Leslie time and he knows she's reaching the age where she no longer wants to be around her older, embarrassing father. Still, he can't help it. She's his little girl regardless of how big she gets.

It's the second week in October and they're walking to school, like they have every other morning when he's not on shift, when she turns to him. "You know, dad, you don't have to walk me to school anymore. I'm older now. I can walk myself," she offers matter-of-factly. She was a mini Gabby, that's for sure.

He knew this conversation was coming. He'd been preparing himself for weeks, really. Yet he would be lying if he said he wasn't disappointed. He understands though. Hell, if he were in the fifth grade he certainly wouldn't want his old man walking him to school and kissing him in front of his friends. He realizes in that moment that he has to let her be a big kid, that perhaps it's time to give her some space and let her go to school on her own. He knows she has friends that would be walking with her, so she wouldn't be going alone. They'd be careful. He knows.

He knows.

It doesn't hurt any less.

Especially when he goes to kiss her that morning and she quickly wipes at her cheek. "Dad," she groans. "Not in front of my friends. You're so embarrassing."

"Okay. Okay," he says, his hands up in defeat. "Well, can I at least have a hug?"

As quickly as she runs into his embrace she's out of it. He watches on as she makes her way towards her friends and they begin trudging along into the building. When she reaches the top step he calls after her. "Have a good day, munchkin." He laughs to himself when she shakes her head at him. Yup, definitely mini Gabby.

And just like that, their routine is over.

He knew this day would come.

He just wished it didn't have to.

-x-

He and Gabby are lying on the couch one night watching the Blackhawks game and drinking beer when he hears Leslie's door open upstairs. She had a big party that night at her friend Tiffany's house. Almost the entire junior class was going and she couldn't stop talking about it for weeks. It was endearing, really, how excited she was.

He, on the other hand, was a nervous wreck. There were going to be boys at this party and while she would never admit it to him, he was sure there would be alcohol as well. He wasn't going to be a hypocrite and tell her not to drink, Lord knows he had his fun at high school parties, but he wanted to make sure she knew to be safe.

"Don't get in the car with anyone who has been drinking."

"I know, dad."

"Make sure you never walk away from your drink."

"I know, dad."

"Don't drink too much, you want to know where you are at all times."

"I know, dad. Seriously, I'm not a baby anymore. You don't have to treat me like one."

The Hawks had just scored when the sound of heels clicking on the floor diverted his attention away from the screen and towards his daughter. He does a double take. He isn't sure what she has on, but he knows that it is certainly not acceptable attire to leave the house in.

He knows his eyes are bulging out of his head. He can feel it. In fact, he's pretty sure he just aged 10 years.

Shaking his head, he quickly opens his mouth, prepared to tell her to change. "What is that?" he asks, motioning towards her outfit. She had on black high-waisted shorts and a crop top that left little to the imagination. Her heels, at least six-inches, made her shorts appear even shorter and he was tempted to pick up the blanket from the couch and cover her with it.

"It's my outfit," she huffs.

He laughs then.

"Well it's an outfit that you will not be wearing tonight. Go back upstairs and change."

"But-"

"Leslie Rose, I am not allowing you to leave the house like that. I'm sorry but this is not up for discussion."

When she comes back down minutes later in a sundress he nods approvingly. As her friend's mother pulls up in front of the house, she begins to gather her things.

"Be careful," he starts. "And have fun."

The door shuts before he can even get the words out.

-x-

He can't believe his daughter is getting married. That same little girl that would snuggle in his lap after a long day, that he would dance around the house with, or sing Disney songs completely off tune with, was getting married.

He was giving her away.

She looked stunning. Truly. He's not just saying that because she's his daughter. But to be fair she did get the best of both parents. With her long blonde curls tucked behind her veil, and her deep brown eyes lightly decorated with makeup, she looked like the princess that he always knew her to be.

The music is starting and soon he'll be walking her down the aisle and she looks like a mix of anxious and ecstatic. He's not sure what compels him to do it, but he embraces her and begins to sing into her ear.

"There's two things I know for sure: she was sent here from heaven, and she's daddy's little girl."

It was a song that he had sung to her many times. A song both had sung together.

She looks up at him, tears in her eyes, "Dad, you know I'll always be your little girl, right?"

He smiles then. A genuine smile full of emotion.

"I know, baby girl. I know."

That night after the reception, with Gabby tucked under his arms, he quickly swipes at the tears that make their way down his face. He waited his entire life for Leslie. He watched as she laughed, cried, and grew up before his eyes. He wouldn't trade a single second of his life for anything. He knows that he's not perfect. Far from it. But his little girl is the most perfect thing that's ever happened to him. She is perfect.

He looks down at Gabby, lightly kissing her head, and echoes the words that they had said in the hospital all those years ago.

"We did good."